i've never had a bad moment on my mojos, both 15s and 20s. that is to say every time they've released it's been because of a big fall and not releasing would end my knees. never once did they release when i didn't need them to.
now, salomon z12s on the other hand were shit- literally last week i landed a 3 a little bit back seat- not a bail but a bit washed out, i certainly didn't think i was gonna go down. to my irritation my ski pooped off and i ate shit only to find that when i picked up my ski the heelpiece had fucking shattered. at first i thought it had ripped out with the screws but i looked closer and saw that the screws were in place and the binding had literally ripped through the screwhead and shattered. shocking build quality, and as i say, hardly any impact at all...
overall i would say that most brands have decent high-din bindings:
916s and up, p15s, fks etc, tyrolia >15s, duke/jester. these are all fairly tried and tested. don't like vist much. if you don't need a high din, i think p10, p12, fks120 are far better than any other 12 din. if you can't get those then px/axial are the next best thing. all other 12 din bindings i've found to be plastic and not fantastic.